Federal Register / Vol. 72, No. 37 / Monday, February 26, 2007 / Rules and Regulations 8263 

adverse effects of HIRF. Therefore, we 

consider this system to be a novel or 

unusual design feature. 

Discussion 

There is no specific regulation that 

addresses protection requirements for 

electrical and electronic systems from 

HIRF. Increased power levels from 

ground-based radio transmitters and the 

growing use of sensitive avionics/ 

electronics and electrical systems to 

command and control airplanes have 

made it necessary to provide adequate 

protection. 

To ensure that a level of safety is 

achieved equivalent to that intended by 

the regulations incorporated by 

reference, special conditions are needed 

for the Raytheon Aircraft Company 

Model BAe.125 Series 800A airplanes 

modified by Duncan Aviation, Inc. 

These special conditions require that 

new avionics/electronics and electrical 

systems that perform critical functions 

be designed and installed to preclude 

component damage and interruption of 

function because of both the direct and 

indirect effects of HIRF. 

High-Intensity Radiated Fields (HIRF) 

With the trend toward increased 

power levels from ground-based 

transmitters, and the advent of space 

and satellite communications, coupled 

with electronic command and control of 

the airplane, the immunity of critical 

avionics/electronics and electrical 

systems to HIRF must be established. 

It is not possible to precisely define 

the HIRF to which the airplane will be 

exposed in service. There is also 

uncertainty concerning the effectiveness 

of airframe shielding for HIRF. 

Furthermore, coupling of 

electromagnetic energy to cockpitinstalled equipment through the cockpit 

window apertures is undefined. Based 

on surveys and analysis of existing HIRF 

emitters, an adequate level of protection 

exists when compliance with the HIRF 

protection special condition is shown 

with either paragraph 1 OR 2 below: 

1. A minimum threat of 100 volts rms 

(root-mean-square) per meter electric 

field strength from 10 KHz to 18 GHz. 

a. The threat must be applied to the 

system elements and their associated 

wiring harnesses without the benefit of 

airframe shielding. 

b. Demonstration of this level of 

protection is established through system 

tests and analysis. 

2. A threat external to the airframe of 

the field strengths identified in the table 

below for the frequency ranges 

indicated. Both peak and average field 

strength components from the table are 

to be demonstrated. 

Frequency 

Field Strength 

(volts per meter) 

Peak Average 

10 kHz–100 kHz ........... 50 50 

100 kHz–500 kHz ......... 50 50 

500 kHz–2 MHz ............ 50 50 

2 MHz–30 MHz ............. 100 100 

30 MHz–70 MHz ........... 50 50 

70 MHz–100 MHz ......... 50 50 

100 MHz–200 MHz ....... 100 100 

200 MHz–400 MHz ....... 100 100 

400 MHz–700 MHz ....... 700 50 

700 MHz–1 GHz ........... 700 100 

1 GHz–2 GHz ............... 2000 200 

2 GHz–4 GHz ............... 3000 200 

4 GHz–6 GHz ............... 3000 200 

6 GHz–8 GHz ............... 1000 200 

8 GHz–12 GHz ............. 3000 300 

12 GHz–18 GHz ........... 2000 200 

18 GHz–40 GHz ........... 600 200 

The field strengths are expressed in terms 

of peak of the root-mean-square (rms) over 

the complete modulation period. 

The threat levels identified above are 

the result of an FAA review of existing 

studies on the subject of HIRF, in light 

of the ongoing work of the 

Electromagnetic Effects Harmonization 

Working Group of the Aviation 

Rulemaking Advisory Committee. 

Applicability 

As discussed above, these special 

conditions are applicable to Raytheon 

Aircraft Company Model BAe.125 Series 

800A airplanes modified by Duncan 

Aviation, Inc. Should Duncan Aviation, 

Inc. apply later for a supplemental type 

certificate to modify any other model 

included on Type Certificate No. A3EU 

to incorporate the same or similar novel 

or unusual design feature, these special 

conditions would apply to that model as 

well. 

Conclusion 

This action affects only certain novel 

or unusual design features on Raytheon 

Aircraft Company Model BAe.125 Series 

800A airplanes as modified by Duncan 

Aviation, Inc. It is not a rule of general 

applicability and affects only the 

applicant who applied to the FAA for 

approval of these features on the 

airplane. 

The substance of these special 

conditions has been subjected to the 

notice and comment procedure in 

several prior instances and has been 

derived without substantive change 

from those previously issued. Because a 

delay would significantly affect the 

certification of the airplane, which is 

imminent, the FAA has determined that 

prior public notice and comment are 

unnecessary and impracticable, and 

good cause exists for adopting these 

special conditions upon issuance. The 

FAA is requesting comments to allow 

interested persons to send views that 

may not have been sent in response to 

the prior opportunities for comment 

described above. 

List of Subjects in 14 CFR Part 25 

Aircraft, Aviation safety, Reporting 

and recordkeeping requirements. 

■ The authority citation for these 

special conditions is as follows: 

Authority: 49 U.S.C. 106(g), 40113, 44701, 

44702, 44704. 

The Special Conditions 

■ Accordingly, pursuant to the authority 

delegated to me by the Administrator, 

the following special conditions are 

issued as part of the supplemental type 

certification basis for Raytheon Aircraft 

Company Model BAe.125 Series 800A 

airplanes modified by Duncan Aviation, 

Inc. 

1. Protection from Unwanted Effects 

of High-Intensity Radiated Fields 

(HIRF). Each electrical and electronic 

system that performs critical functions 

must be designed and installed to 

ensure that the operation and 

operational capability of these systems 

to perform critical functions are not 

adversely affected when the airplane is 

exposed to high-intensity radiated 

fields. 

2. For the purpose of these special 

conditions, the following definition 

applies: Critical Functions: Functions 

whose failure would contribute to or 

cause a failure condition that would 

prevent the continued safe flight and 

landing of the airplane. 

Issued in Renton, Washington, on February 

12, 2007. 

Ali Bahrami, 

Manager, Transport Airplane Directorate, 

Aircraft Certification Service. 

[FR Doc. E7–3231 Filed 2–23–07; 8:45 am] 

BILLING CODE 4910–13–P 

DEPARTMENT OF TRANSPORTATION 

Federal Aviation Administration 

14 CFR Part 39 

[Docket No. FAA–2006–24034; Directorate 

Identifier 2006–NE–05–AD; Amendment 39–

14959; AD 2007–04–26] 

RIN 2120–AA64 

Airworthiness Directives; Pratt & 

Whitney PW4077D, PW4084D, PW4090, 

and PW4090–3 Turbofan Engines 

AGENCY: Federal Aviation 

Administration (FAA), Department of 

Transportation (DOT). 

ACTION: Final rule. 


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8264 Federal Register / Vol. 72, No. 37 / Monday, February 26, 2007 / Rules and Regulations 

SUMMARY: The FAA is superseding an 

existing airworthiness directive (AD) for 

Pratt & Whitney PW4077D, PW4084D, 

PW4090, and PW4090–3 turbofan 

engines that were reassembled with 

previously used high pressure 

compressor (HPC) exit brush seal packs 

and new or refurbished HPC exit 

diffuser air seal lands. That AD 

currently requires replacing the HPC 

exit inner and outer brush seal packs 

with new brush seal packs, or replacing 

the HPC exit brush seal assembly with 

a new HPC exit brush seal assembly. 

This AD requires replacing the HPC exit 

inner and outer brush seal packs with 

new brush seal packs, using either 

original equipment manufactured 

(OEM) parts, or FAA-approved part 

manufacturer approval (PMA) parts. 

This proposed AD also applies to 

engines reassembled with a PMA HPC 

exit inner and or outer brush seal packs. 

This AD results from a request to 

include PMA HPC exit inner and outer 

brush seal packs and to include the 

engines with PMA parts already 

installed, in the AD. We are issuing this 

AD to prevent uncontained engine 

failure, damage to the airplane, and 

injury to passengers. 

DATES: This AD becomes effective April 

2, 2007. 

ADDRESSES: You may examine the AD 

docket on the Internet at http:// 

dms.dot.gov or in Room PL–401 on the 

plaza level of the Nassif Building, 400 

Seventh Street, SW., Washington, DC. 

FOR FURTHER INFORMATION CONTACT: 

Antonio Cancelliere, Aerospace 

Engineer, Engine Certification Office, 

FAA, Engine and Propeller Directorate, 

12 New England Executive Park, 

Burlington, MA 01803–5213; telephone 

(781) 238–7751; fax (781) 238–7199; email: antonio.cancelliere@faa.gov. 

SUPPLEMENTARY INFORMATION: The FAA 

proposed to amend 14 CFR part 39 with 

a proposed AD. The proposed AD 

applies to Pratt & Whitney PW4077D, 

PW4084D, PW4090, and PW4090–3 

turbofan engines that were reassembled 

with previously used HPC exit brush 

seal packs and new or refurbished HPC 

exit diffuser air seal lands. We 

published the proposed AD in the 

Federal Register on November 20, 2006 

(71 FR 67073). That action proposed to 

require replacing the HPC exit inner and 

outer brush seal packs with new brush 

seal packs, using either OEM parts, or 

FAA-approved PMA parts. That action 

also proposed to apply to engines 

reassembled with a PMA HPC exit inner 

and or outer brush seal packs. 

Examining the AD Docket 

You may examine the docket that 

contains the AD, any comments 

received, and any final disposition in 

person at the Docket Management 

Facility Docket Office between 9 a.m. 

and 5 p.m., Monday through Friday, 

except Federal holidays. The Docket 

Office (telephone (800) 647–5227) is 

located on the plaza level of the 

Department of Transportation Nassif 

Building at the street address stated in 

ADDRESSES. Comments will be available 

in the AD docket shortly after the DMS 

receives them. 

Comments 

We provided the public the 

opportunity to participate in the 

development of this AD. We have 

considered the comments received. 

Request To Add Part Numbers in the 

AD Applicability 

One commenter, All Nippon Airways, 

requests that we add Pratt & Whitney 

and PMA part numbers in the AD 

applicability to avoid confusion as to 

what parts are to be removed and 

replaced. 

We do not agree. We adequately 

identified the parts requiring 

replacement, as well as the unsafe 

condition, in the proposed AD. Pratt & 

Whitney part numbers can be found in 

Alert Service Bulletin No. PW4G–112–

A72–280, Revision 2, dated January 12, 

2007, which we refer to as additional 

information. We did not change the AD. 

Request To Allow Installing an HPC 

Exit Brush Seal Assembly 

One commenter, Pratt & Whitney, 

requests that we also allow installing an 

HPC exit brush seal assembly, in lieu of 

installing an HPC exit brush seal pack, 

to comply with the AD. 

We agree. Compliance with the AD 

can be achieved by installing either an 

HPC exit brush seal pack or an HPC exit 

brush seal assembly. Although installing 

an HPC exit brush seal assembly may be 

more costly for operators, it may be 

more convenient. We changed the AD 

compliance to allow for either 

replacement. 

Used Part Prohibition 

For clarification, we added a used 

part prohibition paragraph in the 

compliance section. It states that engine 

reassembly with used OEM or used 

FAA-approved PMA HPC exit inner and 

outer brush seal packs with OEM or 

FAA-approved PMA new HPC exit 

inner and outer brush seal lands, is 

prohibited. 

Conclusion 

We have carefully reviewed the 

available data, including the comments 

received, and determined that air safety 

and the public interest require adopting 

the AD with the changes described 

previously. We have determined that 

these changes will neither increase the 

economic burden on any operator nor 

increase the scope of the AD. 

Costs of Compliance 

We estimate that this AD will affect 

76 Pratt & Whitney PW4077D, 

PW4084D, PW4090, and PW4090–3 

turbofan engines installed on airplanes 

of U.S. registry. We also estimate that it 

will take about 9 work-hours per engine 

to perform the parts replacement, and 

that the average labor rate is $80 per 

work-hour. Required parts will cost 

about $99,990 per engine. Based on 

these figures, we estimate the total cost 

of the AD to U.S. operators to be 

$7,653,950. 

Authority for This Rulemaking 

Title 49 of the United States Code 

specifies the FAA’s authority to issue 

rules on aviation safety. Subtitle I, 

Section 106, describes the authority of 

the FAA Administrator. Subtitle VII, 

Aviation Programs, describes in more 

detail the scope of the Agency’s 

authority. 

We are issuing this rulemaking under 

the authority described in Subtitle VII, 

Part A, Subpart III, Section 44701, 

‘‘General requirements.’’ Under that 

section, Congress charges the FAA with 

promoting safe flight of civil aircraft in 

air commerce by prescribing regulations 

for practices, methods, and procedures 

the Administrator finds necessary for 

safety in air commerce. This regulation 

is within the scope of that authority 

because it addresses an unsafe condition 

that is likely to exist or develop on 

products identified in this rulemaking 

action. 

Regulatory Findings 

We have determined that this AD will 

not have federalism implications under 

Executive Order 13132. This AD will 

not have a substantial direct effect on 

the States, on the relationship between 

the national government and the States, 

or on the distribution of power and 

responsibilities among the various 

levels of government. 

For the reasons discussed above, I 

certify that this AD: 

(1) Is not a ‘‘significant regulatory 

action’’ under Executive Order 12866; 

(2) Is not a ‘‘significant rule’’ under 

DOT Regulatory Policies and Procedures 

(44 FR 11034, February 26, 1979); and 


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Federal Register / Vol. 72, No. 37 / Monday, February 26, 2007 / Rules and Regulations 8265 

(3) Will not have a significant 

economic impact, positive or negative, 

on a substantial number of small entities 

under the criteria of the Regulatory 

Flexibility Act. 

We prepared a summary of the costs 

to comply with this AD and placed it in 

the AD Docket. You may get a copy of 

this summary at the address listed 

under ADDRESSES. 

List of Subjects in 14 CFR Part 39 

Air transportation, Aircraft, Aviation 

safety, Safety. 

Adoption of the Amendment 

■ Accordingly, under the authority 

delegated to me by the Administrator, 

the Federal Aviation Administration 

amends 14 CFR part 39 as follows: 

PART 39—AIRWORTHINESS 

DIRECTIVES 

■ 1. The authority citation for part 39 

continues to read as follows: 

Authority: 49 U.S.C. 106(g), 40113, 44701. 

§ 39.13 [Amended] 

■ 2. The FAA amends § 39.13 by 

removing Amendment 39–14729 (71 FR 

49335, August 23, 2006), and by adding 

a new airworthiness directive, 

Amendment 39–14959, to read as 

follows: 

2007–04–26 Pratt & Whitney: Amendment 

39–14959. Docket No. FAA–2006–24034; 

Directorate Identifier 2006–NE–05–AD. 

Effective Date 

(a) This airworthiness directive (AD) 

becomes effective April 2, 2007. 

Affected ADs 

(b) This AD supersedes AD 2006–17–08, 

Amendment 39–14729. 

Applicability 

(c) This AD applies to Pratt & Whitney 

PW4077D, PW4084D, PW4090, and PW4090–

3 turbofan engines that were: 

(1) Reassembled with a previously used 

original equipment manufacturer (OEM) or 

part manufacturer approval (PMA) high 

pressure compressor (HPC) exit inner brush 

seal pack; and 

(2) Reassembled with a new or refurbished 

OEM or PMA HPC exit diffuser air seal inner 

land. 

(d) These engines are installed on, but not 

limited to, Boeing 777 airplanes. 

Unsafe Condition 

(e) This AD supersedure results from a 

request to include PMA HPC exit inner and 

outer brush seal packs and to include the 

engines with PMA parts already installed, in 

the AD. This AD action is the result of a 

report of oil leaking into the high pressure 

turbine (HPT) interstage cavity and igniting, 

leading to an engine case penetration and 

engine in-flight shutdown. We are issuing 

this AD to prevent uncontained engine 

failure, damage to the airplane, and injury to 

passengers. 

Compliance 

(f) You are responsible for having the 

actions required by this AD performed at the 

following compliance times, unless the 

actions have already been done. 

(g) Replace the HPC exit inner and outer 

brush seal packs with OEM or FAA-approved 

PMA new HPC exit inner and outer brush 

seal packs, or an OEM or FAA-approved 

PMA new HPC exit brush seal assembly, as 

follows: 

(1) By 3,000 cycles-in-service (CIS) since a 

used HPC exit inner brush seal pack and a 

new or refurbished HPC exit diffuser air seal 

land were installed in the engine, or by 

March 31, 2007, whichever occurs later; 

however 

(2) If on March 31, 2007, the used HPC exit 

inner brush seal pack coupled with a new or 

refurbished HPC exit diffuser air seal inner 

land assembly has not accumulated 3,000 

CIS, then by 3,000 CIS, or December 31, 

2008, whichever occurs first. 

Used Part Prohibition 

(h) Engine reassembly with used OEM or 

used FAA-approved PMA HPC exit inner and 

outer brush seal packs with OEM or FAAapproved PMA new HPC exit inner and outer 

brush seal lands, is prohibited. 

(i) Information on replacing HPC exit inner 

and outer brush seal packs can be found in 

the Pratt & Whitney Alert Service Bulletin 

No. PW4G–112–A72–280, Revision 2, dated 

January 12, 2007, and in the engine overhaul 

manual. 

Alternative Methods of Compliance 

(j) The Manager, Engine Certification 

Office, has the authority to approve 

alternative methods of compliance for this 

AD if requested using the procedures found 

in 14 CFR 39.19. 

Related Information 

(k) Pratt & Whitney Alert Service Bulletin 

No. PW4G–112–A72–280, Revision 2, dated 

January 12, 2007, also pertains to the subject 

of this AD. 

(l) Contact Antonio Cancelliere, Aerospace 

Engineer, Engine Certification Office, FAA, 

Engine and Propeller Directorate, 12 New 

England Executive Park, Burlington, MA 

01803–5213; telephone (781) 238–7751; fax 

(781) 238–7199; e-mail: 

antonio.cancelliere@faa.gov for more 

information about this AD. 

Issued in Burlington, Massachusetts, on 

February 16, 2007. 

Peter A. White, 

Acting Manager, Engine and Propeller 

Directorate, Aircraft Certification Service. 

[FR Doc. E7–3017 Filed 2–23–07; 8:45 am] 

BILLING CODE 4910–13–P 

DEPARTMENT OF TRANSPORTATION 

Federal Aviation Administration 

14 CFR Part 71 

[Docket No. FAA–2006–26311; Airspace 

Docket No. 06–AWP–19] 

RIN 2120–AA66 

Modification of Class D Airspace; Luke 

Air Force Base, AZ 

AGENCY: Federal Aviation 

Administration (FAA), DOT. 

ACTION: Final rule. 

SUMMARY: This action modifies Class D 

airspace at Luke Air Force Base (LUF), 

AZ. This modification is necessary to 

contain and protect circling maneuvers 

for Category E aircraft executing these 

maneuvers in conjunction with 

Standard Instrument Approach 

Procedures (SIAPs) at the airport. 

DATES: Effective Date: 0901 UTC, May 

10, 2007. The Director of the Federal 

Register approves this incorporation by 

reference action under title 1, Code of 

Federal Regulations, part 51, subject to 

the annual revision of FAA Order 

7400.9 and publication of conforming 

amendments. 

FOR FURTHER INFORMATION CONTACT: 

Francie Hope, System Support 

Specialist, Western Service Center, 

AJO2–W2, Federal Aviation 

Administration, 15000 Aviation 

Boulevard, Lawndale, California 90261, 

telephone (310) 725–6502. 

SUPPLEMENTARY INFORMATION: 

History 

On December 7, 2006, the FAA 

published in the Federal Register (71 

FR 70910) a notice of proposed 

rulemaking to revise the Class D 

airspace at Luke Air Force Base, AZ. 

Interested parties were invited to 

participate in this rulemaking effort by 

submitting written comments on this 

proposal to the FAA. On January 11, 

2007, a notice of proposed rulemaking 

correction was published in the Federal 

Register (72 FR 1301), changing the 

legal description to better describe the 

requisite airspace. No comments were 

received. This modification is the same 

as that proposed in the notice. Class D 

airspace areas are published in 

Paragraph 5000 of FAA Order 7400.9P 

dated September 1, 2006, and effective 

September 15, 2006, which is 

incorporated by reference in 14 CFR 

71.1. The Class D airspace designation 

listed in this document will be 

published subsequently in the Order. 


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